The Gorilla Legend Beast is one of the Legend Beasts.
Long, long ago, the Gorilla Beast was a pet of the Fire Tribe with others until the war and Chi water caused many of his gorilla brothers to evolve. Because he knew that they all had inner chi, the Gorilla Beast chose not to drink the Chi water and instead left Chima with seven other Legend Beasts, vanishing into the Outlands, but said to return when Chima needed them most.
When the Dark Tribes were created, he was captured along with the other legend beasts so the chi falls would not restart while they stole all the Chi. The Gorilla and Lion Beasts were often to escape the Crawlers, but were often recaptured. One of these occasions was when the Bats had just returned from another attack on Chima, and they together escaped. Scorm sent the Spiders to recapture them.
The Gorilla Beast was held in the Spider Canyon in a trap made by Spinlyn, with him breaking the webs and the only way for the Spiders to hold him was to constantly spin new webs with their Spider Stalker until the eight Chima heroes found him along with the Rhino Beast. By disguising Rogon's Rock Flinger as a giant fly, they were able to distract the Spiders long enough for the Gorilla Beast to break the webs, but Spindle realized this and got the other Spiders to get back and continue to tie him up, but Gorzan stopped them using Chi. The Gorilla Beast broke loose and helped him defeat the Spiders with the Rhino Beast and then they escaped to the Outland Base. Lavertus gave it armour to protect his mind from the Scorpion Tribe's venom.
He was ridden by Gorzan to the Scorpion Cave to rescue the Raven Legend Beast. They kept the Scorpions busy while Laval, Lavertus and Razar rescued the Raven Beast. After the Raven Beast helped defeat the Scorpions, they fled back to the Outland Base.
Gorzan later rode him again to rescue the Eagle and Bear Legend Beasts, and thanks to Rogon's Rhino Beast making him smart, he was able to get them a shortcut to the see-saw trap, allowing Gorzan and the Gorilla Beast to hold up the slab of rock the Bear Beast, Laval and Bladvic were on. Unfortunately, the Gorilla Beast was unable to hold it up long. It was longer when Bladvic got the Bear Beast to sleepwalk into the center, but Lavertus unintentionally caused it to walk back and the Gorilla Beast let go. Fortunately, Rogon released the water to break their fall and the Gorilla Beast hopped on the Crocodile Beast to shore and went back to the lair.
Worriz later pit the Legend Beasts against each other to see which was the mightiest, and the Gorilla Beast grabbed the rock off the Rhino Beast, but was tripped by the Crocodile Beast. It then grabbed it, causing Rogon and Bladvic to fall off their beasts, but the Eagle Beast snatched the rock off it, when they all got distracted by Lavertus' cupcakes.
Gorzan rode the Gorilla Beast throughout the final battle in the Scorpion Cave until it collapsed because of Rogon and Scorm. Thanks to Lavertus and Rinona in the Wind Shadow, they were able to escape before it collapsed. They then returned to Chima and restarted the Chi falls, entering Mount Cavora.
Laval, Cragger and Eris later found the Phoenix Fire Temple in Mount Cavora and the Legend Beasts, who had somehow had their armour removed, used their fire power to send them up into the temple to meet the Phoenix Tribe.
The Legend Beasts later attacked Laval and Cragger with their fire power as part of the trial to see if they were worthy of the Fire Chi, which they passed.